TypeError: load_pem_public_key() missing 1 required positional argument: 'backend'

python 实现sign with apple 后端服务时候出现错误  

问题: jwt.decode 导致失败

通过python -m jwt.help 查看当前cryptography 的版本

{

  "cryptography": {

    "version": "2.8"

  },

  "implementation": {

    "name": "CPython",

    "version": "3.7.6"

  },

  "platform": {

    "release": "20.2.0",

    "system": "Darwin"

  },

  "pyjwt": {

    "version": "2.0.1"

  }

}

pyjwt 2 需要  cryptography>=3.3.1,<4.0.0

解决：pip install --upgrade cryptography  

更新到   cryptography-3.4.6